title: FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells.
abstract: Efficient repair of DNA double strand breaks and interstrand cross-links requires the homologous recombination (HR) pathway, a potentially error-free process that utilizes a homologous sequence as a repair template. A key player in HR is RAD51, the eukaryotic ortholog of bacterial RecA protein. RAD51 can polymerize on DNA to form a nucleoprotein filament that facilitates both the search for the homologous DNA sequences and the subsequent DNA strand invasion required to initiate HR. Because of its pivotal role in HR, RAD51 is subject to numerous positive and negative regulatory influences. Using a combination of molecular genetic, biochemical, and single-molecule biophysical techniques, we provide mechanistic insight into the mode of action of the FBH1 helicase as a regulator of RAD51-dependent HR in mammalian cells. We show that FBH1 binds directly to RAD51 and is able to disrupt RAD51 filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under unperturbed growth conditions to prevent unwanted or unscheduled DNA recombination.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 14300 Prague, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Simandlova
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Zagelbaum
authors.affiliation: Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford OX3 9DS, United Kingdom.
authors.forename: Miranda J
authors.initials: MJ
authors.lastname: Payne
authors.affiliation: Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford OX3 9DS, United Kingdom; Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Wai Kit
authors.initials: WK
authors.lastname: Chu
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 14300 Prague, Czech Republic.
authors.forename: Igor
authors.initials: I
authors.lastname: Shevelev
authors.affiliation: Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford OX3 9DS, United Kingdom.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Hanada
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York.
authors.forename: Sujoy
authors.initials: S
authors.lastname: Chatterjee
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York.
authors.forename: Dylan A
authors.initials: DA
authors.lastname: Reid
authors.affiliation: Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 14300 Prague, Czech Republic; Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland. Electronic address: pjanscak@imcr.uzh.ch.
authors.forename: Pavel
authors.initials: P
authors.lastname: Janscak
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York. Electronic address: eli.rothenberg@nyumc.org.
authors.forename: Eli
authors.initials: E
authors.lastname: Rothenberg
authors.affiliation: Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford OX3 9DS, United Kingdom; Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark. Electronic address: iandh@sund.ku.dk.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Hickson
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002843:Chromatin / Q000201:enzymology / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D044783:F-Box Proteins / Q000235:genetics / Q000378:metabolism*; D059765:Homologous Recombination / Q000502:physiology*; D006801:Humans; D051379:Mice; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D044783:F-Box Proteins; D009097:Multienzyme Complexes; D004247:DNA; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C495154:Rad51 protein, mouse; D004265:DNA Helicases; C464443:FBH1 protein, human; C553250:Fbh1 protein, mouse
keywords: DNA Damage; DNA Helicase; DNA Recombination; DNA Repair; DNA Replication